This application claims priority under 35 U.S.C. § 119(a) on Patent Application No. 2006-017921 filed in Japan on Jan. 26, 2006, the entire contents of which are hereby incorporated by reference.
The technology presented herein relates to moving object detecting photointerrupters for detecting moving objects, and electronic devices using the same.
Previous examples of this type of apparatus include devices for detecting moving objects based on the detection output from a light receiving element when light is emitted from a light emitting element along a path of a moving object, and light reflected by the moving object that is moving on the path is received by the light receiving element (see, for example, JP 2001-318164A, JP 2002-57367A, and JP 2003-126370A).
There are also devices which make it possible to detect not only the presence of a moving object, but the movement of a moving object (the movement itself or the direction of movement). For example, there are devices in which two sensors 101 and 102 are arranged side by side as shown in FIG. 10 and FIG. 11. When a moving object 103 passes in front of the sensors 101 and 102 in sequence, the moving object 103 is detected by the sensors 101 and 102 one after the other, and the direction of the movement of the moving object 103 is detected based on the sequence of detection by the sensors 101 and 102. If the moving object 103 moves in the direction of arrow A, the moving object 103 is first detected by the sensor 101 and then the moving object 103 is detected by the sensor 102, thereby making it possible to detect that the moving object 103 is moving in the direction of arrow A based on the sequence of detection by the sensors 101 and 102.
The sensors 101 and 102 are each equipped with one set of a light emitting element and a light receiving element, as in the devices described in JP 2001-318164A, JP 2002-57367A, and JP 2003-126370A, for example, light being emitted from the light emitting element, light reflected by the moving object being received by the light receiving element, and the moving object being detected based on the light reception output of the light receiving element at this time.
Accordingly, if the moving object 103 moves in the direction of arrow A as shown in FIG. 10 and FIG. 11, and detection is performed first by the sensor 101, and then detection is performed by the sensor 102, the output from the light receiving element of the sensor 101 changes as shown in FIG. 12, the output from the light receiving element of the sensor 102 changes after the moving object 103 passes a fixed distance Δk, thereby making it possible to detect that the moving object 103 is moving in the direction of arrow A based on the sequence of changes in the detection output of the light receiving elements.
Nevertheless, two sensors 101 and 102 are conventionally provided in order to detect the direction of movement of the moving object, and therefore the number of parts doubles when compared to cases in which only the presence of a moving object is detected. Furthermore, since two sensors 101 and 102 are provided separately, providing a separate circuit for detecting the direction of movement of the moving object based on the output of the sensors 101 and 102 is necessary. Accordingly, simply detecting the direction of movement of the moving object entails an increase in the number of parts, greater structural complexity, greater design complexity, increased mounting space, greater complexity in assembly and tuning, increased costs, and so on.
Accordingly, the present technology has been devised in light of these conventional problems, and it is a feature thereof to provide a moving object detecting photointerrupter capable of detecting the direction of movement of a moving object and a device using the same, without involving an increase in the number of parts or the complexity of the structure, etc.